This invention relates to testing electronic devices and more particularly, to wireless testing of electronic devices using testers and access points.
Electronic devices such as cellular telephones, portable computers, handheld media players, and other devices often contain wireless circuitry. The wireless circuitry may, for example, be used to support wireless local area networking (WLAN) functionality. In a typical scenario, a wireless electronic device may support IEEE 802.11 wireless networking standards (sometimes referred to as WiFi®).
Wireless test equipment is used to test wireless electronic devices. For example, wireless test equipment is sometimes used to perform WLAN testing. A tester may, for example, perform packet loopback testing. In packet loopback testing, control messages are transmitted from a tester to a device under test (DUT) in the form of a number of test data packets. The control messages instruct the DUT to transmit acknowledgment data packets back to the tester. The acknowledgement data packets transmitted from the DUT are then captured by the tester. The tester analyzes the acknowledgement packets using its built-in analysis capabilities to extract radio-frequency parametric data such as transmit power and transmitter constellation error.
As an example, a wireless electronic device such as a cellular telephone may include cellular telephone transceiver circuitry that is used to make telephone calls. The cellular telephone transceiver circuitry contains power amplifier circuitry that transmits radio-frequency (RF) signals to a nearby base station. If care is not taken, a rapid change in heat generated from the power amplifier circuitry may adversely affect the capability of the WLAN circuitry to properly transmit data (i.e., to transmit data having power levels and transmitter constellation errors that satisfy performance criteria).
Conventional arrangements for testing WLAN circuit functionality involve measuring the performance of the WLAN circuitry while the power amplifier circuitry is placed in an active mode that constantly transmits radio-frequency signals or in an inactive mode during which the power amplifier is turned off. The performance of the WLAN circuitry, however, may be most adversely affected when the thermal transient (i.e., the instantaneous change in heat generated by the cellular telephone transceiver circuitry) is maximized. Testing WLAN circuitry performance using this conventional approach is not a rigorous test of WLAN circuitry performance, because leaving the power amplifier circuitry in the active or inactive mode does not maximize thermal transient.
It would therefore be desirable to be able to provide improved ways of testing WLAN transceiver circuitry performance.